Represents absolute copy number and copy neutral variations of groups of samples. aCNViewer recognizes recurrent events through three different graphical outputs: dendrograms, bi-dimensional heatmaps, and stacked histograms. It can’t account for intra-tumor heterogeneity or compare two groups of samples. This tool is efficient in datasets from Affymetrix single nucleotide polymorphism (SNP) arrays as well as whole exome sequencing (WES)/whole genome sequencing (WGS) data.